Buggy code:
public class TextField extends FieldType { protected boolean autoGeneratePhraseQueries ; protected Analyzer multiTermAnalyzer = null ; private boolean isExplicitMultiTermAnalyzer = false ; @ Override protected void init ( IndexSchema schema , Map < String , String > args ) { } public Analyzer getMultiTermAnalyzer ( ) { } public void setMultiTermAnalyzer ( Analyzer analyzer ) { } public boolean getAutoGeneratePhraseQueries ( ) { } @ Override public SortField getSortField ( SchemaField field , boolean reverse ) { } @ Override public void write ( TextResponseWriter writer , String name , IndexableField f ) throws IOException { } @ Override public Query getFieldQuery ( QParser parser , SchemaField field , String externalVal ) { } @ Override public Object toObject ( SchemaField sf , BytesRef term ) { } @ Override public void setAnalyzer ( Analyzer analyzer ) { } @ Override public void setQueryAnalyzer ( Analyzer analyzer ) { } @ Override public Query getRangeQuery ( QParser parser , SchemaField field , String part1 , String part2 , boolean minInclusive , boolean maxInclusive ) { } public static BytesRef analyzeMultiTerm ( String field , String part , Analyzer analyzerIn ) { <START_BUG> if ( part == null ) <END_BUG> return null ; TokenStream source ; try { source = analyzerIn . tokenStream ( field , new StringReader ( part ) ) ; source . reset ( ) ; } catch ( IOException e ) { throw new org . apache . solr . common . SolrException ( ErrorCode . BAD_REQUEST , ( "Unable<seq2seq4repair_space>to<seq2seq4repair_space>initialize<seq2seq4repair_space>TokenStream<seq2seq4repair_space>to<seq2seq4repair_space>analyze<seq2seq4repair_space>multiTerm<seq2seq4repair_space>term:<seq2seq4repair_space>" + part ) , e ) ; } TermToBytesRefAttribute termAtt = source . getAttribute ( TermToBytesRefAttribute . class ) ; BytesRef bytes = termAtt . getBytesRef ( ) ; try { if ( ! ( source . incrementToken ( ) ) ) throw new org . apache . solr . common . SolrException ( ErrorCode . BAD_REQUEST , ( "analyzer<seq2seq4repair_space>returned<seq2seq4repair_space>no<seq2seq4repair_space>terms<seq2seq4repair_space>for<seq2seq4repair_space>multiTerm<seq2seq4repair_space>term:<seq2seq4repair_space>" + part ) ) ; termAtt . fillBytesRef ( ) ; if ( source . incrementToken ( ) ) throw new org . apache . solr . common . SolrException ( ErrorCode . BAD_REQUEST , ( "analyzer<seq2seq4repair_space>returned<seq2seq4repair_space>too<seq2seq4repair_space>many<seq2seq4repair_space>terms<seq2seq4repair_space>for<seq2seq4repair_space>multiTerm<seq2seq4repair_space>term:<seq2seq4repair_space>" + part ) ) ; } catch ( IOException e ) { throw new org . apache . solr . common . SolrException ( ErrorCode . BAD_REQUEST , ( "error<seq2seq4repair_space>analyzing<seq2seq4repair_space>range<seq2seq4repair_space>part:<seq2seq4repair_space>" + part ) , e ) ; } try { source . end ( ) ; source . close ( ) ; } catch ( IOException e ) { throw new RuntimeException ( ( "Unable<seq2seq4repair_space>to<seq2seq4repair_space>end<seq2seq4repair_space>&<seq2seq4repair_space>close<seq2seq4repair_space>TokenStream<seq2seq4repair_space>after<seq2seq4repair_space>analyzing<seq2seq4repair_space>multiTerm<seq2seq4repair_space>term:<seq2seq4repair_space>" + part ) , e ) ; } return BytesRef . deepCopyOf ( bytes ) ; } static Query parseFieldQuery ( QParser parser , Analyzer analyzer , String field , String queryText ) { } public void setIsExplicitMultiTermAnalyzer ( boolean isExplicitMultiTermAnalyzer ) { } public boolean isExplicitMultiTermAnalyzer ( ) { } }

Fix:
if ( ( part == null ) || ( analyzerIn == null ) )